Higher order balance control: Distinct effects between cognitive task and manual steadiness constraint on automatic...

Area of Science:

• Neuroscience
• Biomechanics
• Human Motor Control

Background:

• Postural control is crucial for daily activities.
• Cognitive and manual tasks can interfere with postural stability.
• Understanding how these tasks interact is important for preventing falls.

Purpose of the Study:

• To investigate the combined effects of cognitive load and manual steadiness on automatic postural responses (APRs).
• To determine if cognitive and manual tasks interact during balance recovery.
• To explore the neural mechanisms underlying modulated postural responses.

Main Methods:

• Young adults performed a balance recovery task under varying manual steadiness conditions (high vs. low).
• Participants concurrently performed a cognitive subtraction task or no cognitive task.
• Automatic postural responses (APRs) were analyzed, including body and tray displacement, joint kinematics, and muscle activation.

Main Results:

• Cognitive task performance increased body and tray displacement, with greater hip and trunk movement, and reduced GM muscle activation.
• High manual steadiness reduced tray velocity, trunk displacement, and ankle/hip rotation.
• No interaction was found between cognitive and manual tasks, suggesting parallel processing.

Conclusions:

• Cognitive and manual tasks independently modulate automatic postural responses (APRs).
• APRs are influenced by multiple parallel mental processes, involving higher-order neural structures.
• These findings contribute to understanding the neural basis of balance control under dual-task conditions.